Automobile doorlatch



Nov. 19, 1935.

W. C. MERIDETH ET AL AUTOMOBILE DOORLATCH 2 Sheets-Sheet 1 Filed Nov. 13, .1934

. a g ATTORNEY.

Nov. 19,1935. w. CJQMERIDVETH El AL AUTOMOBILE boosm'rca 'Fi'led Nov. 13, 1934 2 Sheets-Sheet n Illlllllllllllll lllllllllllll 1n I I I 1 I I I INVENTORS By 04m 57,014 544 M10151.

Patented Nov. 19, 1935 UNITED STATES PATENT OFFICE AUTOMOBILE nooaLA'rcn Walter C. Mcrldeth and Oran A. Sidwell, Denver,- Colo.

Application November 13, 1934, Serial No. 752,805

8 Claims. I (01'. 70-29) This invention relates to an automobile door latch. With some types of automobile door latches-an auto thief can, by means of a wrench or other tool. twist the door handle until the-lock is. broken and released. Various locks and latches have been designed which, when locked, release the exterior handle. This allows the latter handle to be freely rotated so that an auto thief can not obtain access by twisting a handle.

Such locks, and latches,however, have beenobjectionable, for when released, the handle may project at any angle which detracts from the appearance of the automobile, and requires a manual adjustment of the misplaced handle when the lockis unlocked or the latch is released. I

The principal object of this invention is to provide an automobile latch which, when locked, will allow the handle to be freeely turned withoutdamage to the lock, yet will automatically I return the free handle to its proper aligned position when the latch or look is released.

Other objects are to provide a cheap, simple, rigid construction for the latch members; and efilcient construction for releasing the exterior handle when the latch is locked from the inside; and a construction which can not be damaged by unauthorized tampering; I

Other objects and advantages reside in the detail construction of the' invention, which is designed for simplicity, economy, and efllciency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the drawings and throughout the description.

In the drawings:--- Y 1 v Fig. i is a horizontal section through the latch case, taken on the line i--l, Fig. 2. Y

Fig. 2 is a vertical section illustrating the latch in the unlocked or released position. This section is taken on the line 2-2, Fig. 1.

Fig. 3 is a simlar section illustrating the latch Fig. 5 is alongitudinal section through the ex- I ternal handle shaft, illustrating it adapted toe key lock. I

Fig. 8 is a similar section, taken on the line 55 4. Fig. 5.

Fig; 7 is a detail'face view of the pinion (i!) of Fig. 5. v

The latch may be designed to suit any desired installation, and may, if desired, be provided with any of the usual cylinder lock mechanisms. As 5 illustrated in Figs. 1, 2, and 3, the key mecha nism has been omitted. A method of installing a key operated mechanism is illustrated in Figs.

5, 6,'and 7, and will belater described.

The latch illustrated in Figs. 1, 2, and 3 is for 10 looking doors of an automobile from the interior of-the car without the use of a key.

The mechanism is installed in a suitable'latch' case 8. An inner handle shaft I0 terminating in an inside handle H; and an outer handle 15 shaft i2, terminating in an outside handle it project from opposite faces oi. the case. A looking bolt projects from one extremity thereof.

The outer handle shaft i2 is journalled in the front face of the case 9, and in an offset plate 58 30 secured to the rear face of the case 9 by means of suitable rivets 60. A spur pinion I5 is secured on the shaft i2 immediately in front of the offset plate 59. The pinion i5 meshes with a rack member ifi'carrying suitable rack teeth l-l along 55 one of its edges. The rack member i8 is suspended from a bell crank lever i8 mounted on a suitable hinge pin IS. The bell crank leve'r i8 is pivoted on a pivot pin 20 from the rear face of the case 9. The other extremity of the bell crank 30 lever i8 carries a crank pin 2i which rides in a notch 22 in the bolt M.

It can be readily seeen that if the shaft i2 is rotated ina clockwise direction (Fig. 2) the spur pinion i5 will travel in the rack teeth H to pull the rack member 16 downwardly, causing it to actuate thebell crank lever l8.- This causes the crank pin 2| to engage the extremity of the notch to pull the latch bolt H inwardly, as shown by the broken line positions in Fig. 2. Thus, operation of the outside handle I! will withdraw the bolt 14. The bolt I4 is returned to its original position when the handle i3 is released by a coil spring 23, the extremity of which engages a projecting shoulder 24 on the latch 45 bolt II. p p

The handle shaft ill is iournalled in the rear face of the case 9, and is secured at its inner extremity to a locking plate 25. The handle is preferably formed with a square extremity 2' so that it will not rotate in the plate 25. The upper extremity of the plate 2 5 carries a link pin 21. The rearward extremity of the latch bolt M carries a similar link pin 28. An open link 29 extends between the link pins :1 and a.

It can be seen that if the shaft III is rotated in a clockwise direction (Fig. 2) it will pull the latch bolt l4 inwardly to the broken line position through the medium of the link pins 21 and 23, and the link 29. Thus the latch bolt l4 can be actuated by movement of the inside handle ll. Actuation in this manner, however, does not move the outside handle l3. This is due to the fact that the notch 22 is of suflicient length to allow the latch bolt to move inwardly without engaging the hinge pin 2|.

We have now described the normal operating functions of the handles I l and I3 upon the latch bolt l4. Means are provided whereby operation of the inside handle H in the opposite direction, or counterclockwise in Fig. 2, will release the outside handle i3 so that it cannot be used to operate the latch bolt l4.

This is accomplished through the medium of the locking plate 25 which is extended downwardly a suilicient distance to be brought into engagement with a ratchet notch 30 formed in a swinging lever 3|. The swinging lever 3| is hingedly secured to the rear wall of the case 8 at 32. The lower extremity of the swinging lever 3| is connected through the medium of a connecting rod 33, with a second bell crank lever or triangular plate 34, through the medium of suitable hinge pins 35 and 36.

The triangular plate is pivoted to the rear face oi the case on a pivot pin 31. The side extremity of the triangular plate carries a link pin 33 which travels in a vertical slot 39 in the rack member IS. The swinging lever 3| is constantly maintained against the plate 25 by means of a spiral spring 40.

Now, if it is desired to disengage the exterior handle l3 so that the latch can not be operated from the exterior of the car, it is only necessary to swing the inside handle ll upwardly. This causes the lower corner of the plate 25 to force the swinging lever 3| rearwardly until the corner engages in the notch 30, as shown in Fig. 3. This action has swung the triangular plate 34 so that the link pin 38 has traveled upwardly in the slot 39 and has swung the rack member l6 out of engagement with the pinion II. The outside handle II can now be freely rotated but will have no effect whatsoever on unlocking or withdrawing the latch bolt l4. i

It is desirable to provide some means for returning the outside handle II to the horizontal or natural position when it is released. This is accomplished by means of a spring actuated lever 4!, which is pivoted at 42 to the rear of the case 9, and is connected with a tension spring 43 at its lower extremity. The lever. 4| connects with a connecting rod 44 which extends to short crank member 45 secured on the inner extremity of the external shaft I2 inside the offset plate I9.

Naturally the pull of the spring 43 causes the connecting rod 44 to continuously return to its extreme "left position on the crank member 45 whenever the exterior handle I3 is released. Rotation of the exterior handle causes the crank member 45 to swing the lever 4|, and increase the tension in the spring 43. Thus, it can be readily seen that the outside handle will always remain in the horizontal position unless acted upon by an external force, and will always return to the horizontal position when the external force is released.

The above construction allows either handle to operate the latch bolt, when desired, without actuating the other handle; it allows the outside handle to be disconnected from the latch bolt, by operation of the inside handle, so that the outside handle cannot operate the latch and it causes the released handle to maintain its proper aligned position at all times. I

To assist in bringing and holding the released handle l3 to alignment, a leaf spring 44 may be employed. This spring bears against a flat face 41 on the pinion l5. Any rotation of the handle shaft I2 causes the extremities of this flat face to press against and bend this spring 43. The spring, of course, resists this bending and in so doing swings the handle l3 back to its normal position when it is released.

In Figs. 5, 6, and 7, a method of applying a key actuated lock to the external handle I3 is illustrated.

In this form of the invention, the handle shaft comprises: a tube 43, to the outer extremity 01 which the handle I3 is attached. A lock cylinder 49 is rotatably mounted in the tube 43, the rotation of which is controlled by any suitably designed pin tumblers 50 actuated by means of asuitable key ii. The lock cylinder 49 is internally threaded to receive a threaded stud 52 5 which is connected to a spline 53. The extremity of the spline 53 fits into depressions 54 formed in the pinion It. The pinion is mounted upon a shaft 55 which passes freely therethrough, terminating in the crank member 44 to which the connecting link 44 is connected. The shaft 55 is bifurcated so as to pass on each side 0! the spline 53.

When the key ii is turned in one direction, it will thread the stud 52 outwardly so as to force the spline 53 into the notches 54 in the pinion Ii. This locks the pinion to the cylinder 43, so that movement of the handle II will be communicated directly to the pinion. When the key is turned in the other direction, the threaded connection between the stud I52 and the cylinder 43 will withdraw the spline 53 from contact with the pinion I! so that rotation of the tube 48 will not rotate the gear i5. I

It will be noted that the connecting link 44 is 5 always connected through the shaft 53 to the tube 43 so that it will act to always return the tube and its handle H to the normal position, regardless of whether the lock is locked or unlocked. It also acts to return the spline 53 to alignment with its notches 54 so that it may immediately return when the lock is unlocked. The spline 53 is formed with projecting ears 5'! which travel in slots 58 in the shell 48, so as to prevent rotation of the spline and threaded stud therein.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention. 60

Having thus described, the invention, what is claimed and desired secured by Letters Patent is:--

l. A door latch mechanism comprising: a latch case; a first handleshaft projecting from one 63 side of said latch case; a second handle shaft projecting from the other side of said latch case;

a bolt projecting from one extremity of said latch case; a lever secured on the inner extremity of said first handle shaft; a pinion on the inner extremity of said second handle shaft; a rack member engaging said pinion and operatively connectedto said bolt so that movement of said pinion in one direction will draw said bolt into said case; and movement in the other direction 15 will not affect said bolt; means for withdrawing said rack member from contact with said pinion when desired, said latter means comprising: a swinging lever adapted to be contacted by the lever on said first handle shaft; and a connecting rod extending from said swinging lever to an operable connection with said rack bar.

2. A door latch mechanism comprising: a latch case; a first handle shaft projecting from one side of said latch case; a second handle shaft projecting from the other side of said latch case a bolt projecting from one extremity of said latch case; a lever secured on the inner extremity of said firsthandle shaft; a pinion on the inner extremity of said second handle shaft; a rack member engaging said pinion and operatively connected to said bolt so that movement of said pinion in one direction will draw said bolt into said case; and movement in the other direction will not aifect said bolt; means for withdrawin said rack member from contact with said pinion when desired, said latter means comprising: a swinging lever adapted to be contacted by the lever on said first handle shaft; and a connecting rod extending from said swinging lever to an operable connection with said rack bar, said connecting rod extending from said swinging lever.

3. A door latch mechanism comprising: a latch case; a latch bolt projecting from one extremity of said case; a spring urging said latch bolt to the projected position; a handle shaft projecting into said latch case; a pinion secured on said handle shaft; a rack member meshing with said pinion; a bell crank lever swingingly supporting said rack member at its one extremity; a pin carried by the other extremity of said lever, said pin traveling in an elongated notch in said bolt so as to allow inward movement of said bolt without actuation of said bell crank lever; and

means for withdrawing said rack from contact with said pinion when desired. r

4. A door latch mechanism comprising: a latch case; a latch bolt projecting from one extremity of said case; a spring urging said latch bolt to the projected position; a handle shaft projecting into said latch case; a pinion secured on said handle shaft; a rack member meshing with said pinion; a bell crank lever supporting said rack member at its one extremity; a pin carried by the other extremity of said lever, said pin traveling in an elongated notch in said bolt so as to allow inward movement of said bolt without actuation of said bell crank lever; means for withdrawing said rack from contact with said pinion when desired; and a spring actuated member 'eccentrically mounted on said handle shaft so as to return the latter to its original position when 5 released.

5. In a door latch mechanism having a handle shaft and means for releasing the handle shaft from the latch mechanism when desired, means for turning the released shaft to a predeterm mined position of rotation comprising: a push rod eccentrically connected to said handle shaft at its one extremity; and a spring; exerting a constantvpush on said rod so as to cause it to turn said shaft to its normal position when it is 15 released the connection of'said push rod with said *handle shaft being such that said shaft may be rotated entirely around in either direction.

'6. In a door latch mechanism having a handle shaft and means for releasing the handle shaft from the latch mechanism when desired .so;,that it may be completely revolved, means for turning the released shaft to a predetermined position of rotation; and resilient means for releasably a holding said shaft in said position.

7. In an automobile door latch mechanism; a latch bolt; a handle shaft; a pinion on said handle shaft; a vertically movable rack; a bell cranklever translating the vertical movement of u said rack into horizontal movement of said bolt;

a second handle shaft; a projecting plate on said second shaft; a swinging lever adapted to be contacted by said plate; and a connecting bar transmitting the movement of said swinging lever to said rack so as to swing it out of engagement with said pinion when said second handle shaft is turned in one direction.

8. In an automobile door latch mechanism: a latch bolt; a handle shaft; a pinion on said handle shaft; a vertically movable rack; a bell crank lever translating the-vertical movement of said rack into horizontal movement of said bolt; a second handle shaft; a projecting plate on said second shaft; a swinging lever adapted to be contacted by said plate; a connecting bar transmitting the movement of saidswinging lever to said rack so as to swing it out of engagement with said pinion when said second handle shaft is turned in one direction; and means for locking I said second handle shaft in the latter position.

. WALTER C. MERIDETH.

ORAN A. SIDWELL. 

